This contract will ensure that all of the laboratory components of the NIAID-funded clinical trials networks are performing virologic assays in a valid and reproducible manner. This mission is made even more important by the expansion of NIAID clinical networks and grants into international resource-limited settings, where basic standards of clinical virology laboratory testing vary widely from country to country, and by the increasing number and complexity of the assays being used throughout the world. There is also a need to standardize and evaluate new virologic methods to ensure their comparability to the older versions that have been in use by NIAID clinical trial network laboratories. Since modifications of the FDA-approved versions of these assays are often being sold outside the US and are being used in many non-US laboratories, these modifications must also be evaluated. Lower cost alternative assays and point-of-care assays will become necessary in order to sustainably monitor the large numbers of people who are/will be on anti-HIV therapy. There is a need for evaluation of these new technologies. NIAID-supported clinical trial networks depend on the VQA for the proficiency programs and for the assay evaluation studies. The VQA communicates with all laboratories on matters relating to proficiency testing (see numbers in the next section) and collaborates with a subset of the laboratories to perform multi-site evaluations of virologic assays and methods. The VQA also supports NICHD-funded laboratories as well as WHO HIV drug resistance laboratories.